


Nipped In The Bud

by ScarlettsLetters



Series: Chair Week [1]
Category: Iron Man (Movies), Marvel (Comics), Marvel Cinematic Universe
Genre: Ankle Cuffs, Bottom Tony Stark, Chair Bondage, Dirty Talk, Dom Steve Rogers, Dom/sub, Forced Orgasm, Hardcore, M/M, Medical Kink, Milking, Nipple Clamps, Nipple Piercings, Nipple Play, Nipple Spanking, Nipple Torture, Orgasm Delay/Denial, Riding Crops, Rope Bondage, Stony - Freeform, Tony Wants This, Top Steve Rogers, Training, Vacuum Pumping, size queen
Language: English
Status: Completed
Published: 2018-03-29
Updated: 2018-04-02
Packaged: 2019-04-14 14:55:09
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 19,143
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14138394
Author URL: https://archiveofourown.org/users/ScarlettsLetters/pseuds/ScarlettsLetters
Summary: Tony keeps secret how sensitive his nipples are. When Steve finds out, he decides to train Tony to come uncontrollably by nipple stimulation alone.





	1. Chapter 1

Never a smart idea to invite Steve Rogers’ unerring attention to a weakness. A lifetime -- fine, lifetimes -- of training on the battlefield gives him an unerring radar for chinks in a man’s armour.

If it were only the armour were literal, he might stand a chance. Easy to repair a bad seal or a roughly operating joint, or to reconfigure the nanotech shielding around a critical weak point. _I do that every damn day_. But no, Steve arrows in a weakness -- totally accidental, a bit of observant recognition, _not like I meant to show it_ , _he just notices everything_ \-- and holds on like a pitbull to a choice toy.  

Tony slugs down a mouthful of his protein shake  and pretends to listen to the podcast streaming into the kitchen. World news squeezes up against business reports, stock tickers, things he rarely ignores. But the slow vibration in his chest is a maddening distraction due in no small part to the faint electrical impulses set off by the reactor right through his skin.

The drink is a bit chalky and a lot less vile than the energy concoctions he whipped up in the past to keep himself healthy, and it beats a morning shot or coffee in quantities that Steve frowns at. Thanks to Captain Rogers, he's picked up a health regimen that includes a rather balanced breakfast. The blond knows more about the contents than he does; all he knows is that he really would like to hide behind the mug.

Alert as he eats his toast, Steve listens to the ongoing affairs in places crippled by war, bad government, and a depressing lack of strapping blond men wielding a big package in their tight pants. Tony loves that view. It might even be enough to prove God really does exist. Either way he’ll spend plenty of time on his knees if he plays his cards right.

“You even listening, Tony?”

“Hmm?”

“I guess not. I’m gonna wash up my dishes and head down to _Epsilon_ , okay?” he says.

Instantly Tony’s cheeks flush and he tips the mug up to keep his cool, or the illusion of cool intact, when he very much lacks any kind of chill at all. _Epsilon_ is one of the six fortified practice rooms in the tower that he personally designed to the specifications of a very angry super-soldier taking out his temper at full bore.

Steve gets a nod and a muttered, “Gotcha.”

 _Epsilon_ gets the business man’s blood pumping like nothing else. _No accident he chose that one. Steve doesn’t have accidents_. Suddenly eating breakfast becomes an all engrossing task. Visualizing that oiled blond hammering on a punching bag is always delightful, but _Epsilon_ is different. The practice room is more like a lab, the best fucking soundproofed of them all, the one hooked up to the rail-mounted 3D printers.

 _Shit_.

So, weakness. Anyone else might have let the short intake of breath pass. Might not have noticed, but Tony knows better than to think those warm azure eyes miss anything at all. Which, when he gets down to it, is one of those traits he loves about Steve as much as it completely aggravates him.

Totally natural to make a sound after they squeezed out of a post-mission shower, and he reached for one of the fluffy towels large enough to wrap a Clydesdale in. He was trying not to sneak looks at the sculpted calves and immaculate perfection of Steve Rogers’ buttocks, wondering what kind of routine a human being needed to even come close to getting that exquisite balance of firm glutes and mouthwatering curves. _And what did Mom say about staring? Always gets you in trouble,_ and it certainly did when the captain caught him gaping like a hungry schoolboy.

He snapped the towel up to finish blotting off the water, vigorously tugging the hem side to side to hurry up. No one else on the team can be in and out of a shower as fast as their blond leader, except maybe Sam and Bucky, and the mere notion of showering among _them_ launched a tingling web through his stomach.

Unfortunate timing that the image happened just as the towel roughed over his chest like a rasping cat tongue. Hence, the sigh.

Tony knows full well the look landing on him wanted to know the story behind the sound, and he demurred then. Like he was going to admit upfront how tender and receptive his nipples are. He ducked his head and made a noise about being late to the debriefing, figuring the matter is closed. Yeah right, no chance of that; foolish to hope, when he knows full well Steve cares intimately about everyone’s well-being on and off the field. Even if he won’t get to it today, he always does.

Which leads, of course, to all kinds of trouble.

Tony would be lying if he didn’t crave a bit of that now and then to break up the week. Nothing else like trouble spices up the routine of managing a multi-billion dollar company at arm’s reach or shouldering the burden of rescuing the world from cosmic threats and idiots playing at villainous games.

Steve wears casual attire that still manages to hang better on his idealized frame than any model slouching down a runway. His plain white t-shirt and dark jeans are every bit the equal to Tony’s finest suits, though he dresses down in the finest Louis Vuitton has to offer. Hell, his jeans probably cost more than Steve’s flat.

Rinsing a plate and putting it back in the cupboards, the blond offers that faint, knowing smile before he’s on his way. _Caught_ , just like always. The private crook of his mouth might as well be a flashing red sign and a stream of texted instructions. Intrigue hooks Tony better than anything else, and he dreads knowing what Captain Rogers has in mind almost as much as he craves the knowledge.

Remaining shake downed in a gulp, he washes out the mug rather than leave it for Friday to vaporize bacteria off of. Another change since moving into Steve’s sphere, he takes on more of these chores without complaining. His heartbeat thunders through his veins as the cold water dances over his fingers.

“Friday, initiate blackout on floors two to four,” he says.

“Very good, Mr. Stark.”

“I need you to clear my schedule until evening.”

A harmonious burst of blue light dances across the wall to confirm sweeps of varied events. As an afterthought, he adds, “And block out Steve’s, too. With his permission.”

“Confirming with Captain Rogers.” Friday falls silent for a minute, a minute in which Tony leans over the sink and thinks of stock figures and acquisitions for the coming week rather than the fact his cock stirs against his pants.

By mutual consent, he cannot touch himself to seek relief, for all he might just hump the rounded bevel of the countertop for a little relief. Steve hasn’t seen fit to give him any attention to his throbbing length this week -- not since the shower, and not hard to draw a correlation between refusal to answer an unspoken question and a hell of a case of blue balls.

“Captain Rogers agrees to the calendar wipe,” Friday sings, and his pulse goes through the roof. “Mr. Stark, your vitals show elevated levels of cortisone and adrenaline. While you’re within acceptable physical parameters, the sudden change in your blood pressure could cause you to fall or temporarily lose consciousness.”

It’s her nice way of saying his blood flow went completely south, and he waves her off, trying not to run for the elevator.

 

* * *

 

No sooner does he step into the practice room than Steve’s voice reaches him.

“Present.”

Inhibition once locked up his knees, but throughout his training, Tony learned to quell those hesitations. Better than he thought, since his legs fold and he drops to the floor on the spot. The rebound jostles his cock and his balls cupped snugly inside those four thousand dollar trousers. He bites his lip as he adjusts his stance, pushing his knees apart. Steve prefers about hip width, so that’s more or less what he gets.

He gets the adjustments slow and every ticking second to fit into position will be played out on Tony’s flesh -- kinda the point, given how chaste and gentle his boyfriend has been since that fateful shower. Cuddling and a comforting arm wrapped around him at night is good and well for the soul, but the body corrupted by carnal pleasures needs so much more than that.

Steve knows insolence when he sees it, and he never loses that parade stance looming over the dark-haired man on his knees.

“You care to tell me why you’re here?” he asks. Tone light, an opportunity to fess up comes and goes.

Tony doesn’t look up, his gaze riveted onto the way the denim moulds to the long curves of Steve’s cock. The serum made him that big, he’s almost sure of that. Else those pretty nurses would have never let him out of the infirmary back in the war. “Doc keeps saying cardio is good for my health.”

“Stark.”

Out comes _that_ voice, the commander-in-chief dressing down a recruit that sets Tony’s head spinning and his balls tightening up. God, yes, that’s the best.

“How ‘bout you tell me.”

A huge, warm hand grips his chin and adjusts his gaze upward to meet disappointment and, beneath the eclipse of stern regard, a definite luster of passion. They both have their roles on the stage, and the man who punched Hitler two hundred times plays his mastery to perfection.

“That’s ten strokes. I’ll add ten more for every infraction. Say yes if you understand.”

“Yeah.”

Tony’s answer comes out slurred by the thumb pad pressed to his lower lip, pulling down in a broad stroke. Not kissing the whorl of the fingertip is so hard, but he allows Steve to shape his mouth how he will.

“Ten. Let’s try this again. You’re going to tell me what's going on.”

“Going on?” A beat later, the grip firming on his chin, he adds, “Sir.”

“Ten more. That’s thirty, Stark.” Good to know they both have the presence of mind to do the math. Shutting off the internal mathematical processes in his head is tough, but Tony tends to get inaccurate when his arousal crests past a certain point.

Steve is unblinking and calm, radiating control as he releases Tony’s chin and steps back. Beyond him, a table holds an array of inconspicuous lumps and bumps draped under his leather jacket. Straying more than a glance invites punishment, and thirty strokes is enough even for Tony.

“Tell me happened after the shower on Tuesday.”

His tongue dredges his lower lip, feeling the imprint of Steve’s thumb still, a mark set upon him. Tony shifts a little, surreptitious as he tucks his heels under his buttocks. Pulling on his gluteal muscles parts the cheeks and gives a delicious strain on his hole. The hole Steve neglects to slide so much as a thin plug inside, depriving him of that much stimulation when he absolutely fucking needs constant attention on the little pucker.

“Ten more. Forty total.” Steve circles him in a slow, unhurried orbit.

“I got out and dried myself off too fast. Took myself by surprise, that’s all.”

The answer comes out incomplete, hesitating as he freezes, a deer under unwanted attention from a predator.

“I see. Why didn’t you say something?”

“Wasn’t that important, sir.”

Not the right answer, but Tony harbours a low burn for punishment and anything to have those big hands wrapped around his hips or neck or cock, gripping him tight as he trembles at the invasion of his ass by that thick cock or long finger.

“We’ll see.” Steve retreats to the table to fetch two white towels, neither very large. He sets the rolls aside, innocuous bundles pressed up to the brown leather sleeve. “Strip.”

One word carelessly thrown as a command and Tony practically bursts into action. He starts with his jeans, unhooking the button from the tight eyelet, gauging how the hell to pull off the snug material without snagging his stiff dick.

He hoists himself to his knees and works his jeans down, barely aware of the ghostly retreat of his shirt until It’s too late to stop the hem from sneaking up his torso. The cotton brushes softly across his ribs, gathered by a fist behind his back. The scouring lines round his mouth into a circle, panting for breath, and he can’t say no -- _who would say no, but shit,_ _he’s so fucked right now._

He almost wheezes in the same little half gasp when the ribbed fabric catches on his nipples and drags from beneath. The shirt stretches, caught on the little barriers, and pulls up with just enough resistance to angle the resisting nubs back against the areolas. Leaving the undersided nice and exposed to the tension, which he takes like a hoof to the gut.

“Ah.” Steve hums the sound behind closed lips.

Mountain stillness descends upon Tony, his pulse hammering coppery in his ears. The jeans shimmy down his hips, peeled open before his hands go slack. His cock visibly throbs arrow-straight in front of him, demanding its due.

Torture on his nubs ends when the shirt ghosts up over his head, pulled up and lifting his arms with the gesture. The red garment ends up folded and slung over Steve’s broad forearm, and Tony shudders at the exposure. His nipples are small, already contracting in the coolness.

“Tony.”

“Yes, sir.” He doesn’t look up.

“Tell me how you feel right now.”

The direct command leaves no wiggle room, not with the thermonuclear detonation throbbing in twinned time on his chest.

“Hot, sir.” Fighting to keep the quiver from his voice is fucking near impossible. “My cock is so hard it hurts. My hole feels tight. Twitching. I want you to jack me off.”

Limned in the diffuse light of the practice room, Steve looks like a gentle saint, beckoning the faithful to lay their cares at his feet. He nods and then gestures to a chair Tony failed to notice.  
  
“Go sit there.”

Getting to his feet is a trick when hobbled by his jeans. Told to strip, he figures pushing them down won’t earn him any more spankings or whatever his boyfriend has in mind. And if it does, the clench of his pucker reminds him he can take that much. He never ends up pushed past his endurance.

Surely the towels aren’t for his load, which tends to be copious. Maybe for Steve. The soldier can produce a huge volume of cum and the very thought of that has his cock dripping webs of precum from the tip.

He steps out of his jeans and stumbles to the chair, which certainly doesn’t belong among the punching bags or free weights in equipment storage. The last time he saw was in the study or the facility library, a stately thing, all high-backed and broad-armed.

Sitting wooden in it, he spreads his knees to give his aching balls a break. No access to his ass, then. Something doesn’t add up.

“Put your hands on the arms.”

His heartbeat spikes again as he complies, his forearms resting against the firm teak curving forwards. His longest fingers just reach the carvings fanning along the support. The padded back splat fits into the hollow of his spine disturbingly well, but before he can ask a question, Steve reaches down to brush the damn towel lightly over his nipple.

He cries out, unable to bite back that treacherous noise.

The terrycloth barely touches his feverish skin and the little nub shrinks, tightening up at the touch. Drawn in lazy circles, the sensation makes him unable to process the question asked over his head.

“Ah… Ah, could you please say that again? Sir?”

Tender strokes remove the top layer of his composure while the towel barely touches the strained nub.

“You didn’t mention this.”

“No,” Tony struggles for words. Speaking is hard when he wants to crawl away from the towel or beg Steve for his tongue. “They’re a bit sensitive.”

“What are?”

 _No escape from this. Fuck_. His hips are rocking slightly as everything on his chest wall burns under warm, prickling fire. “My nipples.”

Impatience flickers across that beautiful face. Steve’s thumb and pointer finger dwarf the small nodule they capture, squeezing down until the pain erupts along the nerves and he stabs the air with his cock, jouncing, writhing.

"Say it again properly, Tony.”

Tony bites his lip and arches, grunting through the warm spread of red heat. The world is a blur as his cheeks heat up. “My nipples are sensitive, sir.”

“You like the towel?”

“No.” Half-truths he blurts out are followed up immediately. “Yes. They’re so sensitive, I don’t know.”

Steve twists the bud a quarter to the right, half to the left, toying with the plump little lines. He cannot hold still by that point, gripping the arms of the chair for dear life. Every frisson of burning light sinks deep and spreads out, a tickle demanding his ass lift and his cock seek succor. None is to be had, but it doesn’t matter.

“Have they always been this sensitive?”  
  
“Uh, n- _no. God_ , fuck, that’s so much.”

“Then how long?” Steve releases the nub, and it springs back to a stout point. Once more he picks up the towel, drawing the line out between his hands.

“The arc reactor always makes them this bad.” Tony would pretend at indifference but his eyes lock on the white cloth approaching. How can he steel himself against that inexorable, damning torment? “Always tender.”

His words break off into incoherent whimpers when Steve takes the soft edge of the hand towel and starts briskly rubbing it back and forth over the assaulted nipple. He pushes back against the chair strongly enough the thing would fall over if not bolted to the floor.

Fuck. _Fuck_. Steve planned this, which means he planned everything, and every thought spins in Tony’s head like a carousel. They dance and drop in a blur.

“Keep your hands down.”

He needs more and wants more, even as he would crawl away.

“Please!”

Not their safeword -- no _bosun_ or _quark_ to banish the experience, but he’s never felt so close from just a brushing touch. The chafing doesn’t slow.

“Do you think you could get off this way?” Steve asks, curiosity bleeding through the stern focus.

“I d-don’t know.” Tony tosses his head back, straining, his chest pushed out in a curve to take the assault that shifts from horizontal to diagonal lines. “I never tried. Maybe. When it’s just me, I stop.”

“Do you want me to stop?”

Would he, if Tony asked? The notion stirs a deep well of horror and he shakes his head, even though the little nub stands out pink and firm.

The siege continues, finished edge vertical against the flat tip. He grunts again when the towel teases the underside of the nipple, enough to make him grip the chair white-knuckled.

Steve stares into his blushing face. “Say yes or no.”

A gulp of breath, he strains for even the word. “No.”

“You’re blushing, Stark. So here’s how this goes.” The instructor’s voice descends on him, an avalanche pulling Tony to focus the best he can while he fights the spiralling ascent. “You tell me how much you can take. What you think about when you play with your tit flesh.”

The emotional toll hollows out whatever sass remains, and he breaks in a spill of words. “A lot. I get rough." These touches, the tender kind are so much worse.  "I don’t cum from them. When it’s too hard to touch them, I jack off or use a prostate massager.”

When the first words begin, the towel slows its assault on his tenderized nub. He gains enough space to breathe, but barely, and his gaze remains fixed on Steve’s face for fear of losing his train of thought and just drooling all over his fat, stiff nub.

“Yeah?” A tender brush of the thumb over the hugely receptive nerves makes Tony jump in his chair again.

“Unh, fuck, yeah. Light touches are worse than hard ones.”

Obliging the experiment, Steve squeezes the other unattended nipple. Might as well have linked up alligator clips, the  charge shoots over the azurine arc reactor and ignites the untended point. Tony arches stiff and throws his head back at the slow torsion, left gasping when that ends with a pinch.

He really starts to whine in earnest when the towel brushes over the one besieged point, licking from the top in fluttery passes. His hole burns, greedy for filling, and he struggles not to blow his load then and there.

“Do you like me playing with your tit flesh?”

“Fuck.” A pinch ends, Steve pulling his hand back, and he about lurches forward after the retreating touch. The room echoes with his shout: “Yes! Please, sir, yes!”

“Please?”  
  
“Please play with my tits,” he repeats the words, and the taboo breaks open a whole new realm in his lust-addled brain. Yes, he wants Steve to toy with him, fulfilling the unspeakable words.

Steve puts the towel down over his forearm, draped casually. “I need you to wait for a few minutes while I get ready. Do you think you can hold still for me when I start playing with you?”

Tony holds those guileless blue eyes, measuring the weight of trust, and slowly shakes his head.

“I didn’t think so either. That’s okay. You always tell me what you can take, and we work with that,” the blond kisses the top of his head.

 _This_ is why he subjects himself to torments beyond description and humps the padded chair upholstery, waiting impatiently for the return. Steve takes charge of binding him to the arms and legs of the sturdy wooden seat, securing his ankles under several loops of bright red rope.

His wrists receive a different treatment, clamped by thick leather cuffs linked to the support. Another pair of cherry-red ropes come out, wielded with precision around his forearms until he is firmly anchored. Gauntlets race from the cuffs up to his elbows.

“Isn’t this a bit excessive?” he manages to get out with a chuckle.

“Sweetheart, you feel like whining at me around a cock gag?”

Steve pauses in his work with an offer anything but casual in nature, a reprimand hot on the heels of securing the guide ropes through solid steel eye-bolts in the floor.

Tony’s eyes practically fall out of his skull. “Y-you…”

“Does my slut need a fat cock gag to concentrate on?”  
  
He bites the corner of his cheek until practically bleeding. Greed blurs his vision again. Would Steve get a cast of his cock made, something in silicone to attach to a panel gag? Would he even be able to _breathe_ with that monster jammed in his throat? Maybe the tip would stand out every time he swallowed.

Tony bowed his head, whispering, “Only if you want it, sir.”

A pinch anointed his left nipple, renewing the flagging heat to a fresh blaze. “I want to hear you begging for everything. Tell me what you want.”

The last addition is placed quickly, the wide silicone band snapped into place at the root of his cock. He grunts at the cock ring that Steve pulls down into place with perfunctory skill, checking for the snug fit. Underneath its onyx cuff, his balls earn a warm palming and he holds his breath, almost certain those will be bound too. But no, Steve withdraws.

“Sir?”

“Today’s about your nipples.” Steve returns to the tables. “Making them fat, thick, and bright red as cherries. They need to be trained, just like your cock. Just like your hole was.” 

Without that ring, Tony would cum then and there. “St-Steve.”

“These,” he taps the small, tight nodule, “should be stiff and begging to be sucked. Pinched. By tonight they should be big enough to proud of.”

His eyes roll back as Steve starts to strum the points with his fingers, batting them around. Every little sensation sparkles with hidden electricity dancing into the shafts.

He grinds into the chair with little circles as Steve toys with him.

“You’re going to ejaculate from only your tits being played with. If not tonight then you spend every night practicing until you get off,” Steve says softly. “I have plans to leave your nipples permanently hard, but we have a full day ahead of us.”

The sting of fingers smacking the bud makes him reel back into the moment, and he moans. Finding the right word takes a moment but Tony manages through the blissful sting.

“One.”

“One, that's good."

Thirty-nine to go. For that, the blond goes to fetch a thin black crop off the table. He whisks aside his coat to reveal a panoply of toys, a dish of ice cubes gone to melting and a pair of weird, twisted cones made of gold wire. Tony stares at the plastic cylinders bundled up with clear tubing long enough that Steve halts.

He considers Tony strapped down to the chair and the selection, taking the cylinders. A hidden smile curves his mouth as he lifts the thick plastic tube, smearing the seal with lube from the pump bottle on hand. The process he repeats with the other, and the brunet has an astoundingly good idea of where those cylinders end up.

He ends up far from disappointed when the first is pressed to his right nipple, and Steve squeezes the pump ball.

“I’m glad you thought of that,” he chuckles. “They’ll be much more responsive after vacuum pumping.” Every squeeze bleeds air out from the thin tube, pulling the meat of the pink nipple deeper.

Tony tries not to groan, watching with awestruck fascination at the reddening of his captive flesh. When the last of the air is pulled out, the process repeats on the other nipple and he arches his back. Steve disengages the tube from the couplings, leaving the clear glass pair standing out from his chest.

He has hardly long to wait for the next preparations, for Steve picks up the crop and starts tapping the cylinders. Shocks roll down into his captured flesh, going straight into the receptive nerves.

“Ah!” His cry breaks out at every tap and soon he endures a barrage lightly raining down, sensitive flesh handling. Far more than forty strikes, but these are so lightly they hardly count, only enhancing how exquisite every sensation is.

Steve pauses now and then to pull on the tubes, toying with the vacuum seal. He drags out Tony’s nubs into conical formation and the brunet struggles to hold still in his rapt excitement. One snaps free and he stares at the plump nub swollen to double its size.

“Oh fuck.”

“That’s just a start, Tony. We can do so much better.” Steve prods the wrinkled areola and puffy nipple with the tip of the crop, then smacks it down three times in fast succession on the throbbing point.

Striking with quick precision takes a few seconds for Tony to even process, and he twitches in the chair, unable to even raise a hand to defend himself. The lubricated cylinder comes back, pumped out until the stiff point fills half the tube and he grinds his hips for relief.

Relief that’s not coming. Steve resumes tapping to keep Tony thoroughly distracted from his ringed cock. His tender nubs magnify everything, and with the constant spanking of the crop on every side of the tubes, he thrashes in futility in bondage. 

He loves the sight of his big cherry nipples standing out. They look fat and mouthwatering instead  of small. He wants them plump, fat, obscene. He  only hopes Steve feels the same.

An eternity passes -- just nine minutes in reality -- before the first pair of tubes come off with a bubbling pop.

The next size up will be necessary, Tony knows, because he filled the last. His nips are no longer small but lush, those of a woman. He’s seen enough to know, sucked them and clamped them to make his lovers squeal and writhe.

These are his. His fat nipples. He thrusts his chest out and Steve shakes his head, tenderly picking up the cloth and rubbing the terry cotton over each nub to remove the coating of lube.

“Fuck!” Tony shouts louder than he meant to, but the sensitivity is another magnitude higher. “Sir, fuck, I can’t-- I can’t--”

He receives a finger pressed to his tongue and he wraps his lips around it, sucking desperately while taking the torture on the abused points. The outer layer of skin feels aflame and more tender than he’s ever managed, and this is just the beginning.

The next pair of cylinders are manhandled onto his chest, using a different coupling system altogether. Hydraulic, this one, and Steve turns the pump so he can watch a needle jump on a round dial to measure the air pressure. What all those numbers translate into are stiff, fuckable nipples in his head and big, reddened shafts filling up the tubes.

_How many tubes are there? Will he just keep stretching my nipples?_

He whines by the end of it, barely able to sit still for the pleasure and pain humming on his chest.

“We’ll give those ten minutes.” Steve flicks one of the cylinders, earning a groan of appreciation. “No more. In the meantime, let’s keep you occupied.”

Hope springs to life -- _occupied_ means so many possible holes filled -- but nothing prepares Tony for seeing a pair of stretchy silicone cradles wrapped over the tubes. They look like figure eights, empty spaces waiting for something. His inquiring moan lifts, high even to his ears.

“You just wait a moment,” Steve murmurs.

“ _More_.”

With a sigh, the blond reveals a pair of small plastic eggs attached by black wires to a control box, simple in design. Tony knows an egg vibrator when he sees one. Each one slides in tight up against the glass tubing and the silicone web, pushed in and forced down right up against the base of each nipple.

The two wires spindle around one another for  a decent weight tugging on the cylinders, but far from breaking their ironclad grip. His nipples tilt down to the weight, and Steve places the boxes snug up against his dick. He tucks them to either side, and smiles.

Tony can’t shake the anticipation eating up his brain. “I'll cum… My nipples and my cock…”

“You should feel a bit, yeah.” Steve thumbs the control pad until each vibrating egg hums to life with a noisy chatter. He bypasses the moderate setting and settles on high for both. "Let's get them really stretched. We have work to do." 

Hearing any response over that vigorous clatter where the plastic strikes off the glass cylinders will be hard. He goes to sit on the table, legs spread wide to give the bound sub a view of his jeans.

Tony is already whining as he watches his boyfriend take his cock in hand and stroke so slowly.

It’s gonna be a long ten minutes.

 


	2. Nips In the Air

**Summary for the Chapter:**

> Steve has plans to push Tony past the breaking point, if he doesn't come first. Tony, of course, wants more.

**Notes for the Chapter:**

> Dedicated to Places, who inspired this slipping down a very dark hole to Wonderland. Please note corporal punishment with a riding crop features heavily in this chapter, but Steve isn't out to break skin and leave bloody trails.

Ever wanted something so bad you might chew off your own arm or leap through a plate-glass window to have it?

Tony counts down the time down to the hundredth of a second on the digital clock mounted on the wall of the _Epsilon_ training room. _Four minutes, fifty-six seconds_.

Sweat drips down his temples, reducing the fine dark hairs there to tiny porcupine spikes. The clock seems like a safe place to direct his attention, whereas everywhere else only enhances the predicament of his situation, which may just be the exact point of his boyfriend’s nefarious, insidious plans. Captain America may be the iconic hero of democracy, but today he demonstrates a level of cunning on par with the HYDRA masterminds he meant to defeat, designed by the long-ago scientists of the war effort -- _including good old Dad, can’t forget to thank him, bless you for all your other sins_.

Tony never thought of himself as much of a bondage connoisseur before Steve. Now he can’t imagine life without the taste of rope and snug caress of leather cuffs.

He really ought to measure time as BS and AS, given how deep an impact the idealistic blond war hero leaves on his life. Every day takes on a totally different shape than the dark times of compounding excess when he stumbled, hungover, through pointless meetings interspersed by drinking binges, orgies with a starlet of the hour, and bursts of technological innovation, feverishly pursuing some fresh new idea. _Before Steve_ days could end on a bender in the lab, JARVIS tutting about the general disarray of his clothing and unshaven state.

He won’t be going anywhere without Steve’s say so. Movement is nigh to impossible anyways, the only choice he holds being where he chooses to look. The loud harmonics of vibrators clattering on glass resonate through his aching pecs and rattle in his teeth, forcing him to dance within his confinement. Two plastic eggs fed by powerful batteries hum against his areolas, subjecting his swollen nipples to high-blast pulses of sensation. Their battery packs tuck against his balls, tickling vibrations running up the twisted cords forking in a Y up to his tortured nubs.

 _Fuck. Fuck._ He loves this as much as he hates it.

 _After Steve_ is the current stage where time crawls forward. It’s funny how time perception dilates when someone fixates on something. Like, say, having your nipples tickled from every direction without a damn thing you can do about it. He checks the clock again, hopeful. _Four minutes thirty-one seconds._ He’s going to die before he ever reaches zero. That’s all but certain.

Tilting his head back to stare at the training room ceiling enhances how rigid his arched body remains against a formal chair thanks to four separate spirals of rope anchoring him in an upright position. Legs splayed wide enhance his awareness of his nakedness. Any scrap of clothing he wore downstairs is gone. He loves being exposed and vulnerable in the degenerate corner of his filthy soul.

Steve knows it too. He gives Tony exactly what he wants, the fullest experience for loving depravity.

A shudder trails over his bare torso and the arc reactor throws off a cerulean blaze of light wavering on the ceiling in aquatic bands, highlighting the concealed track embedded among the interlocking tiles. Up behind the tiles hides the apparatus he designed with _Epsilon_ specially in mind, an array of 3D printers worked into the hydraulic arms and projectors to allow for immersive combat or physical exercise. Pretty sure Steve knows how to operate it.

* * *

  
Steve, for his part, does nothing to attract attention to himself except by existing in the flesh.  Breathing a touch roughly is music to Tony’s ears, a hypnotic cadence he would meditate on if not for the fact his heartbeat throbs through the whirlwind of suspended metal and the hum on the glass cylinders sealed to his long raspberry nipples.

 _Good._ He should hard and finding it difficult to hold still, considering the whole situation that makes it impossible for Tony to do more than blink and shudder without consequence. This is wholly his blessed, divine, fucking brilliant fault. The blond isn’t anywhere within arm’s reach even if Tony could stretch out his arm -- he can’t, the leather cuffs and gauntleted ropes see to that -- and touch the sculpted perfection.

The captain leans against a sturdy table spread by all the tools of a twisted mind, his jeans open far enough to masturbate. Almost lazily his hand rises and falls, knuckles brushing up against the parted bronze zipper framing the concealed pouch of his balls. Steady pistoning regular as a musician’s metronome would be another reliable way to count down the remaining time until those cylinders unseal from his nipples.

The other reason Tony daren’t look forward: that glorious cock in proportion with the rest of his Olympian physique -- scratch that, an Olympian would be jealous of that masterpiece of a toned, trim body defining everything masculine. Just the edge of his white t-shirt laps over the waistband of his jeans, and that makes a perfect contrast to the long shaft gripped by big fingers capable of spanning Tony’s neck.

He loves watching Steve jerk off as much as he hates being deprived of an opportunity to contribute, interposing his hand between spread thighs to cup heavy, hairless balls or gather up the precum and massage the sticky, slick substance into the thick veins under his fingers. Being forced to look and not touch frustrates him as much now as when he was a child in his father’s lab, denied from playing with any prototypes capable of exploding.

Steve taunts him just by being there. He wants Tony with his mouth slack and eyes glazed, begging in broken words to worship that cock with his tongue and lips. Promising up anything for the right to touch and taste. Anticipation slays Stark's restraint so, frankly, he’d rather count the tiles on the ceiling and pretend like everything is under control when a glance confirms he teeters on the edge.

Better that than staring down at his cock pointing at his belly, the dark crown pointed accusingly at his face. The reminder pulls him back to the raging heartbeat throbbing through his stiff shaft. Instinctively he keeps trying to move his hand to stroke but Steve thought of that weakness as he has everything else, and thick leather cuffs thoroughly bind his wrists to the arms of the chair.

“How you doing over there, Stark? Need something to help you focus?” Steve asks.

The first time he said a word in five minutes after applying the cylinders and Tony snaps his attention over, making the mistake of wriggling side to side in the chair, itching a point between his shoulder blades. That makes his nipple cylinders dance and pull on the distended nubs filling the clear glass tubes, wringing out a sound of tense frustration through his clenched jaw.

“Got it under control,” he forces a reply out with some difficulty.

Another desperate glance at the clock confirms his torture is nowhere near ended, and his nipples already resemble nothing like the dark, small points he feels some embarrassment about. Their hypersensitivity is the lone saving grace, but these swollen nubs are at least double the size of his nips at their fattest. The tubes put a thrill through him as much as a spark of dark, shifting desire spilled like molasses down his chest. They burn in their way.

Steve shakes his head and turns to the sturdy table, laid with all sorts of interesting objects that he physically blocks from view.

“I’m sure we’ve got something for that.”

His breath stops in his throat. The bolted chair legs go nowhere despite the restless rolling shift of his hips. Ropes tightly wrapped around his shins and thighs prohibit much motion, but his cock waves like a flagstaff, angrily swaying side to side above its fat black silicone ring.

Carrying a bowl propped against his hip, the blond glides up to him. A good tweak on the left cylinder twists Tony’s fat nipple in a lazy corkscrew, the flesh sucked up by vacuum pressure too engorged to resist and still too puffy to maintain its natural elasticity. The suction pulls up on his pectoral and he pants in time as every quarter turn pushes Tony reeling into an explosion of stars signalling not quite pain-not quite pleasure.

Staccato breaths leak from his lips, tongue curled to his palate as he moves. Dignity means holding on without pleading for release, rather than glaring imperiously at Steve. Sweat runs down his temples. He arches away from the chair, offering himself up to the torment -- and when he realizes that, he sags back. That only pulls out his tit in a shallow cone. Flesh burns dully through the numbness, and the cylinder never gives up its lamprey kiss.

The chattering vibrating egg finds new nerves to assault, ones he thought dimmed to a dull glow. Riding the wave of sheer intensity forces the back of his head to tip, finding no support. He can barely slouch without thrusting his nipples out for more of this cruel, devious use and they already respond to the slightest disturbance, let along this prolonged tweak.

Hurts so good. Fuck. A throbbing current of magma pools low in his belly and his ringed cock seems to glow, a white star marked against his lust-addled thoughts.

Steve lets go and the glass tube bounces, pointed at a downward angle instead of sticking straight out, marring the symmetry. Why this matters in the whirling impressions and thoughts run through a blender, he can’t possibly say. Somehow that pinch point is better for forcing the humming vibrations right into the root of his throbbing nipple, the plastic orb dancing in the stretched silicone cradle. The underside of his distended nub always proves more sensitive than the top.

The chair groans as he writhes. “St-steve. Fuck, oh fuck, please.”

“Language.” Remonstration comes with another flick of Steve’s fingertip against the cylinder, a pang shot through him.

“It’s too much. Sir, can’t…” He can’t even think of what to say.

He pants when the other cylinder ends up in those big fingers, twisted back and forth to see whether the heavily lubed seal will break and what happens when it does. Steve watches his expression intently and starts to jerk the cylinder mouth flat to his puffy areola and pulls back out, jerking off his nipple inside its glassy prison.

“You sure? You want me to stop?”

Those warm blue eyes hold such intensity, the only answer comes automatically to his tongue.

“No, sir.”

“Good. You aren’t satisfied with just this, are you?”

Tony’s head lolls back, his tongue snaking along his lower lip. Twinned vibrations pick up force when the eggs are pressed to the glass and he shudders along with them. The pressure builds as the tubes push vertical, directing all the attention on the bases of his distended tit flesh.

A firm tap recalls his attention.

“Tony?”

“Fuck, Steve, no, no.”

“Ten.”

The slip of the tongue nets him more punishment and dimly Tony knows he has forty-nine strokes, forty-nine love-taps or whatever else might be coming to mind. On the table lies a riding crop used on him once, and he closes his eyes rather than whine. Besieged, his oversensitive nipples convey the fiery pleasures straight into his belly and lower, but his hard-on receives no relief.

Time slips away from him, no ally while he writhes in his seat. The cool bowl rests in his lap, the rim pressed up against his cock to press the tip up against his navel, an absurd sight should anyone walk into the room. His hands grip the rounded ends of the chair arms, the only thing he holds any kind of control over. Sounds barely penetrate through his fugue as he grows more aroused in the humming torments bouncing around those fat berry nipples standing out at obscene lengths.

Not obscene enough. He can give more, he knows.  
  
“Please, sir,” he breathes out in a grunt. “Please, more.”

“That’s what I expect. More what?”

The routine hardly holds any surprises, and the prompt really acts as permission for the floodgates to break. He feels pressure on the cylinders again, the dual tug stretching out the engorged nodules bit by bit.

“Make ‘em bigger.” A pause and he collects his thoughts. “Sir, I want bigger nipples.”

“How much bigger, Tony?”

Twisting back and forth at slow speed does nothing to arrest his ascent to a plateau he cannot reach, the emptiness in his ass and the pressure rising in his balls all indicative of responding so well to Steve’s persistent training. Vocalizing needs aloud has been an ongoing work in progress.

“Big.”

A sharp tap sends a powerful jolt through him and he opens his eyes to focus on Steve leaning over him, steady and mildly disapproving, if the line between those golden brows converging together speaks of anything. He quickly licks his lips, eyes held in the crystalline magnetism that commanded troops into dire situations on the Western Front and holds him utterly rapt now.

“They aren’t long enough.” He begins at a whisper. “I want them large, sir. Always hard and puffy and red for you to pinch comfortably. I… I love it when they stick through a t-shirt, like you see when women don’t wear bras. My nipples shouldn’t hide, they need… they need...”

His voice falters and breaks, shame flushing his face.

Steve pulls one of the cylinders out until his tit burns and his nipple, the flushed red point, stretches almost as far as he thinks it can humanly go. Then the seal breaks free and it bursts out of its shell, mesmerizing to his streaming gaze. They both look down at the fat, lush point -- _no, it’s not just a nub now_ , he corrects himself.

Both vibrators drop to the ground. Immediately Steve pinches the base and Tony whines at the pressure, the intense shudder running through him derailing any attempt to speak. He pants as the nipple rolls between thumb and index finger, stretched up by slow motions running from the root to the bulging tip. His hips jerk around uncontrollably in every direction as Steve milks him.

“You need training.”

That dark burr in his ear is perfection, a seduction on the misfiring cylinders as he gets closer to throwing himself away from the cylinders. Tony nods, choking on his own breath and spluttering to another keen when Steve taps the turgid point standing up proud and red from his chest.

“We’re going to need bigger cylinders.”

“Uh-huh,” he agrees.

“You want your nipples stretched, don’t you, Stark?”

Tony gulps for air as his nipples are stroked and he can’t help but look at how big -- how _red_ \- they are, begging for attention. His hands tighten, knuckles white.

“Steve…”

“Say it, Tony.”

“Bigger. Punish ‘em, sir, please.”

“They’re not nearly large enough for you, are they?” Steve asks the question as gently as he can while squeezing hard on both points.

Tony arches in a violent jerk and the chair moves barely at all in response. His body flexes, rigid and hot and glistening in the training room, and Steve leans over to kiss him hard. Their lips meet in a bruising collision, tongues wrapped around one another, the gratitude and the agony spread out in a diffuse nebula of searing lust. He can nearly forget about the pressure saturating a full electrical storm in those two little nubs -- still small, oh gods, not the big pouting slutty nips he wants Steve to turn his full attention on.

They kiss for a lifetime while he whines and groans, sharing up his need, played like an instrument. Steve suckles his tongue as he pulls out the fat nipples straight out and draws half-circles, left and right, forcing them to respond.

His cock jerks and twitches in time, surely noticed by the captain. Tony jitters in the wrapped bondage, unable to stop anything, nor would he want to.

“Gonna be huge, baby. I promise, you’ll get all the attention you can take.”

The stroking continues as Steve steps behind him, dwarfing him in the stately chair. Tony barely bothers to look down at the bowl, his head drawn back to rest against the soldier’s washboard abs. A little lower, he might even risk lapping the erect cock pressed up against the solid wooden backsplat. He hates that chair even more, not so much for binding him as preventing him from filling his mouth with the hot, thick shaft, a way to show appreciation and distraction.

His boyfriend would never admit to it, but he loves the spluttering moans choked by his dick, and the way Tony’s eyes roll back in an orgasm with Steve leaking precum down his throat. Teak polished by every little thrust of Steve’s movements betray any ability for touch, just another deprivation.

“Tsk, stop that.” Maybe Steve can’t read Tony’s thoughts, but he can guess. “We’re working on your nipples, Stark, not me.”

“Can’t a man share?”

He gets a firm pinch on his abused left nipple and cries out, and the other hand joins his right nipple for a series of strumming pinches taking full advantage of their mouth-watering ripeness. Steve’s right, this is all he can focus on right now, and the numbness he initially experience sloughs away into a dramatic, rising blaze across tender nerves. Lightning strobes through pathways wherever those big fingers slide and press down, sparks of sensation flowing across his nipples like the plasma balls from the Eighties.

“You’re gonna cum from your nipples. Only your nipples.”

Tony hangs his head, slack in his bonds.

Steve stands behind him and massages his fat nubs for a good two minutes until the swelling goes down to a slightly less obscene level. He pays special attention to the round circles marked on the rosy moons, easing out the pain. For Tony it’s a little like a massage after a hard workout -- and those moments bond them too, Steve digging his fingers deep into the knotted calf or a charley horse when he pushes himself too far on a run.

Except rarely do those moments make him want to cum his brains out onto the floor.

Tony can barely think when touch departs, the warm presence of the sun passing from the land. He almost tracks the departure of the man to another part of the training room. Instead of staring to ruin the surprise, he keeps his eyes shut. Not knowing has always been a bane of his; his parents hid Christmas presents from him as a child, and not much is different now.

Something scrapes into place and settles, Steve’s footfalls a steady tempo in near proximity. He follows them blindly as a broad arm crossing the chair strokes his tender bellend, and his cock trembles to the tickle of fine hair. Steve must be taking something out of the bowl, but he hardly knows what. He hasn’t looked since that cool porcelain settled atop his thighs.

“Since you were so good about not dropping this, I’ll give you a reward.”

Reward? Tony opens his eyes, just in time to watch Steve press a knobbled brown root to his chest. The rough end presses into the soldier’s palm, a shallow knob sliced almost flat across its outward face. He puzzles for a moment while the root traces over the tip of his nipple, and presses down. The pale golden flesh feels slick on his skin and cool, inward cuts textured to batter the fat bud into a hollow. Juices drizzle over him.

Heavy, moist flesh does its work while Steve twists and turns the root like a lemon juicer. Through his dazed thoughts, Tony slowly gathers the evidence -- the scent sharp on the air, the prickle in his receptive skin, and the ticklish burn spreading out.

“Ginger?”

He takes another tweak to his exposed nipple, contracted to a sadly diminished point from its original length. The whole problem with vacuum suction, it never seems to last. He starts to squirm, disappointment and unease mingled on his expression. Steve leans over to kiss him again, and he groans as the ginger grinds into his skin. No escaping ginger oil, nor the peppery burn it leaves into the tender erogenous zones.

Lube on his tit flesh may be a barrier or helpful, but he can do nothing when a second prepared geode of the root lands on his fat nub. He begins writhing when the burn sets in, the sloppy noises of their hard kisses wresting Tony’s attention from the torturous conflagration shocking his system back and forth. Steve knows exactly what he is about, suckling on his lower lip and scoring it with tender bites.

Time is no friend, not at all. The intensity of the heat spreads as his nipples absorb the ginger oil, and the prickle grows to an all out blaze. His stretched flesh greedily radiates the sensations from which there can be no escape, not with Steve applying the steady focus. Tony’s world exists in three places -- his cock, burning bright; his red-hot nipples, and the hot mouth on his.

When he gets too unruly, squirming against the firm leather cuffs and trying to jerk away, the captain leisurely fucks his mouth with his tongue. The sweeps of that thick muscle dance from his teeth and over his palate, jabbing down towards his throat in a pale facsimile of his cock reaming out Tony’s mouth until he splutters and gags on the shaft the way they both love in their hardest sexual encounters.

His extremities burn and his body dances on an indescribable high by the time Steve dumps the ginger into the bowl. No telling if his own fingers burn. He runs his hand through Tony’s dark hair and pushes his head down until those lust-blurred blue eyes focus on the sheet of reflective glass positioned directly in front of him.

Tony Stark, the dishevelled king, mounts his throne and sits wide-legged like a monarch of yore. Stripped of his clothes, he sees how obscene his situation is: his cock arching above two inches of snug black silicone and the red ropes twisted around his arms and legs. But the star venue, his stinging tits, are already strawberry pink and sticking out.

Steve does the honours of pulling out medical calipers from gods know where, circling around to adjust the metal points. One tooth sinks into Tony’s areola. The cold makes him jump and he tries to jerk back from the cool touch on his flaming nip, but the hand on his shoulder prevents that.

He stares at himself, slack-jawed, as the next point lengthens to take an accurate measurement. Slowly the point slides up to take the measure of the pert bud.

The captain murmurs, “That’s one and three quarters centimeters. A good start.”

“How…” He can’t even think to ask.

“Our target is pumping you to six.”

 _Six?_  Tony’s eyes roll back slightly and he groans again.

“You want that, don’t you, sweetheart?”

Does he? Does the sun rise in the east?

“Fuck yes…” Not enough for Tony, not enough by half. “Sir, fuck me. Please fuck me.”

The calipers snap shut and Steve replaces them on the table. Of the selection remaining to him, he picks up two cylinders of a grade much wider than the previous ones. Tony grinds into the seat of the chair, acutely aware of his hollowness and the pucker of his anus clenched around nothing but desire. He has a starring view whether looking at his desperate reflection in the full length mirror or the way Steve rigs up the next pair of acrylic tubes.

“Tony, you’re going to beg me to pump your nipples to fill these.”

If he could conjure any thoughts through the molten firestorm enveloping him, cradling his conscious thoughts, Tony would. This is so far beyond what he has ever managed on his own. He would stop ten miles back but Steve guides him through the dark and out the other side into a place of unimaginable pleasures described only in the most tantalizing echoes of his consciousness.

The words sing to some black-winged shadow in his soul, uplifting him to the infernal depths of depravity. His nipples can barely tolerate the still air, let alone a fresh coating of lube and the swirl of the tubes through the ginger oil accumulated on the bottom of the bowl. Steve runs the open mouths over each nub, smearing lube across the flesh and earning desperate, hazy cries beckoning him to apply more of the substance.

“Look,” Steve commands him. He does.

Tony licks his bruised mouth, swollen tit flesh framed by the fat cylinders pressing down. He can hardly assist, so each one will receive the treatment in its turn, which may be even better to the stirring draconic coils shifting around in his belly, the feathery sparks lashing his balls. Steve framed over him in a wash of white cotton and strong, bare arms keep the black metal handle and clear tubes from obstructing his view.

How do you begin to beg your lover for culmination of a fantasy you’d barely commit to paper? Stark doesn’t know. He knows the need for an orgasm and pleasing his master, his head bowed in submissive acceptance. “Stretch my nipples, sir.”

Steve inclines his head and squeezes the handle lightly, not a full intake, but enough for the powerful suction to pull out the air a little from the solid plastic. The device is meant to bleed out fluid or air from mechanical objects like brakes -- he’s seen the kind used before -- and he has no doubt, none at all, that if Captain Rogers wanted he could do real and lasting damage on tender flesh. But of course he won’t, only giving Tony exactly what he wants.

He wants to cum so bad. He wants so much.

“You want them big and I’m gonna give you what you want, yeah, you need them good and fat for your crop.”

A full two pumps has him arching, jerking as his areolas and nipples suck up into the acrylic confinement. Yes, that’s _exactly_ what they both want, even as he groans and stiffens, jerking on his bonds. Seconds and minutes slip by as he gurgles, struggling to get some kind of equilibrium between madness and eager degeneracy, the kind of darkness goading him to beg for everything writ in scarlet ink on his soul.

“They hurt, they’re burning, but they’re gonna get so big if you make them stuff those tubes. Sir, you gotta stretch them. This isn’t nearly enough, no. You get them sticking out and take those acrylic collars to keep them big. Don’t let my nips get small, no, I want them so tender, so tender I can cum.”

More air bleeds away and he shakes and pants, the perspiration on his upper lip too hard to lick away. His arms quiver and tremble as the cylinders consume him, each march leaping the length by what feels like an inch or two. Of course that’s impossible, Tony knows, he can’t have nipples long as his thumbs, but some perverse side of him craves that and a pair of gauged barbells or rings.

“Fuck, use ‘me, use my nipples. Stevie, let me cum, let me blow my load,” he’s talking uncontrollably, half aware of what he might say.

The next cylinder placed over his untouched nipple soon joins the immense girth and length of the first, the hazy wheeze of the hydraulic press stretching out the fat nub into place. He can’t help but stare in fixed wonder, his cock leaking copiously despite the silicone preventing him from cumming.

Duty demands service. Steve somehow manages not to coat his face in a fresh load either, though his own cock pulses uncontrollably and he occasionally stops to firmly squeeze the root to divert his own explosive release. Increasingly he stops to stroke and clench his fist around his shaft, orgasm diverted, and then he stares at his writhing, rocking boyfriend.

Tony is a wreck and they’re only halfway done. The two cylinders easily attach to a pair of adjustable chains that loop securely around the acrylic prisons. He pulls the tubes straight vertical with the necklace that he wraps around Tony’s neck, placed without a twist that might cut off the brunet’s airway. His hand exists for that, far more nuanced and controlled, when he wants Tony’s tongue lolling out and eyes empty except for the exhilarating high of an oxygen-deprived climax.

Besides, another surprise lies in store despite stretching his fat, obscene nipples even more. They learned from the Chitauri and he intends to give Tony exactly what he begged for then, and now.

  
The crop lands lightly underneath the right nipple, right along the seal. Steve applies the leather flag with laser precision, bearing down so the springy force splats into Tony’s skin and rebounds up against the cylinder. He’ll feel that in his engorged nipple, and that’s the point. Twenty spanks are to be distributed over the ten minutes of having his nubs pulled and elongated, and another twenty to be distributed after Steve pulls them off.

He takes his time, casually striking on the bound man’s chest. Tony wails loudly and begs for more in broken words, unable to slur more than “No” and “More” through the gurgling pleasure. Aim taken to strike in no place twice gives his bared chest no protection, the cylinders smacked about left and right, pulling on the engorged flesh filling at least half their stout volume. He can’t kick out, he can only watch his ripe, fat raspberry tits swinging all over to the zipping music.

Every blow stings much more than hurts, and when the sting fades, the heat melts into his pink welted flesh and makes his nubs stand up that much the more. Halfway through the session, Steve shifts his attention and pulls out the handle, connecting it to the Y-tube and sucking more of the air out without Tony asking.

He doesn’t need to ask. They both know from the wild shaking of his head and the arching of his body how mad it makes him, mad for sex and craving touch. Steve taps his balls one after the other with the crop to swell them up, bending to suckle on the glossy fat tip of Tony's swollen cock while delivering those well-timed spanks. Tony’s wails fill the room, incoherent as he tries somehow to widen his legs, offering himself up.

Five minutes of alternating lapping and cropping landing on his inner thighs and along his groin have Tony’s skin glowing a bright rose, the sunset shade fading up over his stomach, and back up to his nipples that are nearly lilac from their treatment. He tests the ropes holding him and the bolts with every idle caress of the leather grazing over his ribs and dancing along his sternum; circling his navel leaves him grunting and whining.

Steve holds the crop in his teeth when the clock signals the end of the safe period, ten minutes up and done. Two thick rings lie in the bowl, waiting for his attention. Fishing one out, he works one over the acrylic tube’s connector and rolls it down the fat end. Even this amount of jiggling is torment on Tony’s abused nipple and he groans in a protesting urgency audible throughout the room, vibrating in every fibre of his being.

They’ll have to be quick.

The tight silicone binder fits around the flaring base of the tube. Steve works his fingertip under the seal to break it, and then hauls down the binder to snap around the root of Tony’s nipple. He leaves the tube in place, caught partly by the elastic binder, the better to leave his boyfriend in lust-maddened eagerness.

Besides, a brush now could be prematurely destructive, collapsing Tony’s thoughts into an orgasmic fugue, and the cock ring cannot halt all climaxes, only forestall them. The process the second time around is harder, mostly because Tony _knows_ what comes and he bites his lip and throws himself into a taut bow as much as the cuffs allow. The chair shakes when the second binder constricts his nipple, and they both stand huge and plump.

Both tubes barely stay in place. That’s the point, for Steve wastes no time bringing them down with two fast strikes. The acrylic absorbs most of the crop’s force and speed, but the shock still leaves Tony gaping and his mouth red and wide, eager. The crop lands on Tony’s distended tit flesh and forces the easy, raspberry-red target down. It springs back up, ready for its next strike.

“Oh, fuck, _sweetheart,_ ” Steve whispers.

Tony thrusts his chest out, eyes closed, gripping the chair for dear life. “M-m- _more_.” He is past begging, this is a plea. “ _More!_ ”

One after the other, the blows rain down on the two easy targets, fattening them up as Steve crops them. He loses track at the forefront of his mind and Tony gasps and wails, never sagging back. Twisting and writhing, he is beautiful in his extremity, so brave and so fucking doomed, getting exactly what he wanted.

He needs more. He wants more, his whole world concentrated down to the burning stiff pillars of his nipples -- his titflesh -- under siege, stung and spanked, over and over and over. He’s in heaven and barely capable of more than a scream locked in his throat. Hurts so good.

 _Steve. It's so perfect_. Exactly what he wants. What he needed.

Steve withholds his strength, never intending to harm, only to push Tony right into the pleasured fugue he knows his boyfriend can attain with steady approval. Just when Tony's nubs can't possibly get any bigger, they do under their spanking, growing, bright and eager to be cropped once more. They take their punishment so beautifully, same as the writhing cockslut himself, the indescribable blur of impressions beyond anything like pain or pleasure.

The crop sings to fatten his nubs more and more, rebounding off the swollen tips and smarting along the shafts so they stand out proud. Ecstasy claims its victim of Tony Stark, and Tony delivers himself up the best way he knows how, lurching from trying to flinch from the nipple spanking to seeking to intercept the arc of the whip, taking it, stunned in some tiny coherent scrap of his mind at how utterly perfect he looks. The man reflected at him has enormous, vacuum-pumped nipples getting the spanking he always dreamed of, cropped until blossoming huge. Not even the void got him this big.

When Steve reaches fifty-two strikes, a good number total, the nipples subjected to his affections are glowing red, radiating heat to his tender touches. The sensitivity is evident in the way every brushstroke of his thumb earns a stifled jerk of the bound man's body and a groan. Fingertips brushing over the engorged berry nubs -- _no, they’re distended and plump in every way to be called proper nips_ \-- leave Tony shaking, lolling in pleasure.

He’s so close.

_So. Fucking. Close._

He screams when the tug on the clamps yank his nipples out and higher, elongating them past the point they’ve ever reached. Tony can almost imagine the numbers scrolling and he whines for the calipers again, grunting for more.

The metal device comes back for a moment, squeezed in next to the acrylic collar around the base and the sharp caliper point extended to the flat of his nip. A hard tug pulls the puffy, swollen peak out further, taking the measurement to its utmost. Steve tugs on the chain behind his neck several times, and his voice breaks in fraught pleasure.

Steve takes his own cock in hand and jerks off, quick and fast, barely managing ten passes of his hand.

Tony tilts his head back, the firm pressure making his nipples ache beautifully. He moves just in time to receive a coating of fresh hot cum. Ropes of it splash out down his chest as Steve stiffens, rigid shaft spitting one wave after another, and then another, the volume pouring down the perfect arched moon of Tony’s hairless chest. He seems almost poleaxed by his own release coating Tony’s clamped nubs, spilling down to land in his groin.

“Oh.” Steve Rogers breathes out, gasping. “Tony, I love you.”

Tony can barely pull himself together enough to smile.

“Sweetheart…” He tips his head down. “We’re gonna wreck you.”

He licks his lips as the hot strands dribble lower. “ _Sir._ ”

Steve kisses him almost chastely. "You up for your milking now?"

Tony's fixed pupils widen slowly and he almost goes limp in the chair, every dreamy speck of thought swirling into one obvious answer. "Milk my nipples?"

"Til they squirt."

He just about faints in lightheaded rapture.


	3. Milky Way

**Summary for the Chapter:**

> In his quest to cum, Tony may end up with the biggest nipples possible. Of course, that means Steve subjecting him to more play.

Tony’s nipples burn and he struggles to keep his head up. In the freestanding mirror angled for him to watch, he can’t escape the brutal truth that Steve’s treatment is working beautifully on him. His nipples stick out well over an inch from his body, cuffed to stay fat and thick.

Stand _up_ might be a better description. The chain clamped around the nipple cuffs stretches them hard as it loops around the back of his neck.

Crop marks cross his bare chest, focused around the dark puckers of his areolas. The rings from suction tubes still print his skin, his marks of victory. The wicked sting lies with him still, and he feels like putty, unable to much sag in his bondage chair as long as the cherry ropes around his arms fix him hard and upright.

Steve casually flogs the puffy areolas with a long-stranded blue tawse made of kidskin, and those tails curl up in the best way when he slaps them down across Tony’s pectoral muscle. Normally a deerskin flogger wouldn’t do more than warm his pale skin pink, but the super soldier behind the object swings with greater force than that. Parallel, overlapping lines are closer to red under the white film of cum coating his chest. Every splat brings a broader heat bubbling up to the surface and he shudders in place as that sinks into his oversized nubs.

Ginger oil assures the warmth sinks deep into his chest and he shifts around uncomfortably. The desperate high he experienced before ebbs back, and slipping from the fugue drives him mad.

Normally his nips are incredibly sensitive, responsive to the gentlest touch. He flinches from casual play and ever since Steve discovered this, the blond took on the mission of breaking Tony to cumming by nipple play alone. He rather loves it, as much as he wants to rip free of the chair and flee right now. Past that requires too much thought to formulate any plans.

After three rounds of suction, his nubs no longer look like nodules but long raspberry gum drops a girl would be embarrassed by. Not him. He barely watches the arcing strands land on his other breast, splaying out flat at the impact and rebounding up around the vertically pointed nub.

“More,” he demands in a scathing growl.

Golden brows hitch above the warmest South Pacific blue eyes, and another crack stings on his chest as fifteen soft leather tails flap down with weight to press him back into the chair bolted to the floor. It’s going nowhere, and neither is Steve, who can and _will_ do this all day.

“You ready to cum?”

Not by a long shot. He tears his gaze away from his reflection, chest pink and hot under a coating of Steve’s drying white cum, to the man he loves. Tony jerks his chin at his groin.

“Nope, you’re not getting any more down there.”

“You were happy to suck me off.”

“Mistake,” Steve admits. He twirls the flogger and snaps it straight down instead of the underhand strokes intended for the underside of his favourite targets. “I won’t be doing that again.”

“Why the hell not?”

Tony pushes his luck. He might push the right button and get the crop back, smacking him to the point he grinds his ass in wanton circles upon the chair. The pain would be better than this low grade burn, like a too dim light bulb.

Unfortunately Steve has his number and casually smacks the flogger down on his groin, aiming a little too high. Deep sapphire kidskin pools around the ringed base of that fat shaft, and he twitches in anticipation of something harder, but the one caress is all he gets.

“You got a problem with this?”

“Not enough,” he grunts.

“You get off by your fat nipples and only your nipples, Stark.”

He grabs the arms of the chair and jerks forward, pulse pounding in his veins. “Steve, can’t cum like this. More, please!”

They both hear the desperation running in a vein through his voice. The strain of leaning pulls hard on his nipples, stretching them out almost translucent in spots, an angry red burn that sets him back panting against the chair.

Using the leather-wrapped handle of the flogger, Steve taps the base of each nipple twice. The contact isn’t near enough to give Tony the stimulus he desperately wants, and he thrusts himself up after the fading retreat.

A glance at the clock on the wall and the blond returns his touch to those engorged points, rubbing his thumb up and down in the lightest strokes.

Tony bucks in futility. Rope winding up his ankles to just under his knees keeps him from kicking out at nothing. Steve stands between his spread knees, barely touching the puffy moons and the stiff, elongated points.

“Please,” Stark begs through his gritted teeth. He breathes out  in wheezes, shaking his head from one side to the other.

His boyfriend says nothing, continuing to draw tiny circles on the reddened tips using feathery lightness. Thirty seconds of the torment is normally enough to make Tony flee or reflexively throw his arm up, but fifteen under the normal circumstances has him biting his lip to avoid spitting out curse words.

Steve shows no inclination to stop. Pebbled flesh teases the grooves on his thumb. He blows on the stiff points and Tony swears someone put a battery lead up to him, his toes pressed tight to his feet and his empty hole squeezed shut tighter than a bank vault. Tickling his nipples is too much torture to bear, and he starts trying to pull away with limited success.

Those hands merely follow, and the next five fucking minutes are pure agony as the torture continues by stroking and dancing along the exposed shafts. The underside burns to the ghostly impressions of Steve’s digits running along them, the most contact he allows the converging vees of his fingernails coming to a point just below the root where a crescent stamps deep from the suction.

 _Epsilon_ room is so well soundproofed no one hears the cursing and sobbing ripped from Tony’s throat, and Steve never ceases in his actions.

“Was the flogger better?” he asks only once.

Tears stream down Tony’s cheeks in twin wet tracks, his head tilted back and shoulders tight in defeated defense. He shakes his head, once again trying to pull his knees up without luck.

The proof prods his belly. His cock stands so hard it slaps up against his navel.

Steve pinches lightly at the tips and pulls them out. _He can’t expect a verbal response. No way in fucking hell._

Another strumming gives only the lightest pinch, but to Tony it feels like squeezing two loaves of bread or fisting his dick and the super soldier clenching hard. He hisses a whistling whine, the tenderness a thousand fold stronger from the ginger and his pumping.

“No,” he says.

Casually spiralling his nails around the captive bud, Steve barely toys with his nip. “No what?”

“No, sir, no, no.”

Steve lowers his head and runs his tongue from the tip, over the smooth track of the stretched nipple right down to the cuff. He works at wiggling the cuff sealed tight below the bloated titflesh; that bobbling has Tony’s eyes rolling back.

“This gonna make you come finally, slut?”  
  
It tears a fresh layer off his ego to admit anything, the sweet heat of that velvet muscle rapidly cooling. Tony’s chin touches his chest as he watches his anointed nub try to contract, unable to shrink much at all.

The teasing flicker of Steve’s middle finger carves his conscious thoughts to shreds even though the contact is fleeting and so very light.

“No.” He almost sobs again, fresh tears stinging his eyes. Too intense. Not prolonged enough.

Steve kisses his forehead and nods. He moves out of Tony’s field of vision, leaving the man a wreck in the seat with his chest heaving, breathing wild to the galloping in his pulse.

 _Is Steve disappointed? I can do better. I_ can. He must have failed some kind of test, and that alone is enough to make his lust-addled mind turn over anxiously on the moment. Not that his dick is flagging at all.

He may be halfway to losing his composure completely when the blond returns carrying a hand towel, one wet and another dry. He barely notices the application of the warmer terrycloth to his stomach, wiping away the stained spend of that sticky release. Circles rough away the flaking film to leave his skin scrubbed clean, working gradually upwards to the starburst.

“You get close to getting off, you tell me. This doesn’t count.”

He nods to Steve.

Even this is a cruelty, taking away the badge of Steve’s release. He gulps a wet breath and the blond pauses to roll the dry washcloth into a bundle lengthwise. The bit ends up pressed to his lips and Tony complies, opening his mouth to accept the makeshift gag.

“Good. Keep that in your mouth,” Steve says. Unnecessarily, as it proves.

Tears run even harder down his face, and he’ll be drooling soon too.

Swiped strokes run over his ribs, for the diligent captain never leaves a mess unattended for long. Methodical and diligent efforts strip away the sticky mess until leaving Tony properly clean. The only place that Steve ignores are the fat nipples, drawing narrow spirals and circles around them until the blood is practically burning in the engorged, entrapped points.

Deliberately not touching him where he wants it most, that just ruins Tony. The equilibrium tips and he free falls into frustrated despair, all the endorphins in his veins sending him crashing as Steve keeps edging him to unforetold heights. He moans around the gag even as he weeps.

Clean and broken down to some fugue state, Tony doesn’t even notice the two kisses planted on either cuff except as brushing pressure.

 

* * *

 

Cruelty lies nowhere in Steve’s makeup, for all he serves as an exceptional soldier and a peerless leader.

Erskine was right all those years ago. The super soldier serum he formulated heightens the innate psychological and genetic tendencies, underlining what already existed. When he chiseled away the chaff, he revealed a man of unquestionable integrity driven to do what is needed and right, but never at the expense of others.

Steve killed in his service. How not? But he loathes the loss of every life, and regrets the failure of other non-violent methods. Far be it from him to stand by as Tony falls through a sub drop, though he does not directly seek to interfere with the crashing hormone levels.

Edging has those valleys in shadow to go with the sunlit peaks, and these too will never be navigated alone.

He ducks to kiss Tony’s stretched lips around the gag and runs his fingers through the dark, damp hair to reassure that quiet, still functioning part of his boyfriend’s genius mind he is still safe, still loved.

Tony barely lifts his head, still completely overwrought, with so much more to come. Sometimes a good cry solves everything, and sometimes it signals being overwhelmed by emotion, sensation, fear.

“Boson?” he asks.

The use of their safeword cuts right through the misery, and Tony looks up. Wet, chocolate brown eyes turn up to him, melting under a film of tears. He searches Steve’s face for something instinctively and fails to find it.

His shoulders ease a fraction at that. Just a little, but enough to find comfort.

Slowly he shakes his head, teeth gripping the moistened hand towel. It makes him drool uncontrollably and he despises it for that purpose, as much as he needs so much more.

Steve strokes the soft whiskers of his goatee, tipping his chin up to hold his gaze. “Okay. Spit out the gag and say it if you need to.”

He nods.

“No shame in signalling me, you understand?”

Another nod, one prone to head hanging. Steve reaches to squeeze his nipple and he gasps behind the gag, throwing his head back.

“I mean it. You don’t have to come tonight. We have all the nights in the world to get you there.”

Magic words for Tony. Steve might as well have flipped a switch by presenting him a challenge. He wants to rise the occasion. _Fuck the serum._ Every ounce of his body can meet Steve’s command and exceed expectations, and nothing is going to stop him from mastering this training like he has everything else.

The flare of resolve burns its way through the mask of sorrow, a firework in the dark. Steve smiles fully and truly then, then snaps the clamps off Tony’s nipples.

Triumph turns into a brittle, shaking cry as the tension pops them free.

Steve resumes tenderly stroking and running his nails over the fat nubs standing out in reddened fury at him, and Tony’s cry tapers out into guttural grunts again.

 

* * *

 

Ten minutes and he’s driven to a dreamy state, more physically responsive than mentally. Steve has left him again and his nipples are every bit as swollen as they were then the plastic tubes engulfed his flesh.

His thoughts reduced to slag put a buffer around his awareness for much past his hard on and the throbbing pulse in his cherry nipples.

Steve approaches him from behind, thus his arrival startles Tony somewhat. He tilts his head in confusion and tries to look back even as his nipples end up rubbed firmly with a clear, wet substance thick like an oil. Instantly his focus shudders out from a paused state into awareness, especially as the coolness settles into to something almost icy.

He almost loses the towel gag, his tongue thrusting against his palate as the icicle chill spreads and his nipples stiffen a bit. No, not puffy, but harder in their length and he thinks for an instant the world might implode, reduced down to the span of his arched chest.

The chill hurts and comes as welcome relief, the intense wintery kiss sinking in past the heat built up over time. Unabated desire rips through his nervous system and capsizes any sort of control. Fingers open and close around the chair arms, spasming as his core flexes.

Now the cleaning makes sense. Now the exquisite torment of his nipples being lightly stroked makes all the sense in the world, to prepare him for the next magnitude of action.

Precum glistens on his slit, welling up, but no foray down there to lick it off. Steve instead moves to the side, and he pulls the fat nub out straight out.

Tony tosses his head from side to side, only for the fragrant, familiar scent of leather and the musk of Steve’s skin to engulf him with a frantic, heaving breath. The spice drugs him a little more even though his chest burns and freezes, and that swollen point is ablaze in the pinched fingers.

“Sit still. I have to measure it.” Steve might as well be announcing the night’s meal.

He tries, to his credit, even though his teeth chatter and his toes press tight against his strained feet. Another pair of measurements taken with the calipers earn a humming approval, and he dares not even to imagine how many centimeters or inches or micrometers he has achieve.

“Stark, we haven’t reached the maximum volume we can.”  
  
A disappointed noise escapes Tony’s throat.

“I may have a possible solution. We can start milking your nipples for an hour to see how they grow.”

The idea processes with a bob of Tony’s cock and his eyelashes fluttering in anticipation. Every muscle from his ribs to his knees convulses together, tightening up.

“Or we can work some of Doctor Banner’s solution in to prep you for the milking,” Steve says. He reaches over to massage Tony’s nipples firmly in opposite directions, twisting and pulling on them.

Either way Tony’s nipples will be leaking and his body betraying him at every stage with its arousal.

He starts to pant, and his tongue presses against his lips. The pink tip starts to sag over his full lower lip as Steve works over his fat nubs, jerking them off like tiny cocks.

Steve leans over to whisper in his ear, “The effects are supposed to be rather dramatic and long-lasting.”

_Long-lasting. Big, fat nipples for Steve to fuck with._

He moans and tips his head back, seeking a kiss given to him with rough enthusiasm, tongue jammed down his throat while he groans his approval for the notion.

“Your nipples will get puffy, Stark. You’ll have little cones standing out from your chest.”

Music that plays more beautifully than any piano solo rolls around him. He keeps pushing his chest up in hopes of those talented fingers twisting, but they only stroke the shafts of his nipples in slow motion. His mouth stays open and upturned for the kiss to continue and Steve obliges, going so slow and savouring his mouth.

“Hard,” he moans.

“I’ll have to spank them for you. So they stay big. You prepared for that spanking?"

"Fuck, yes. Sir, yes."

"I hope so. They're going to be abused, Tony. Only a slut has big nipples.”

“Yes, sir, yes, big. They need so much attention.”

“I expected you'd say that. You’ll be unable to keep from coming all the time with them. I’ll have to keep you cuffed.”

“Fuck, please,” Tony doesn’t care what he’s saying.

“You want them double this size, Stark?”  
  
Steve goads him to deliver his wishes aloud, and he can hardly not perform that. He stretches himself up as the pull on the nubs seems to go on forever and he’s taffy to his fantasy, unable to catch his breath for the twisting, rolling cold. So cold, and so impossibly tender. His slickness runs down over his balls, dripping onto the seat.

“More.” It’s his catch word and Steve leans down to suckle one of the nubs, still squeezing and slapping the other one with his fingers to distract him from cumming like a geyser. The pain shocks him less than it should but the heat of that warm mouth scalds him, and he suffers so beautifully by twisting and writhing in his bonds.

“Let’s get you ready to go and good for squirting,” Steve says, planting a kiss on his areola.

He loves this man and wants no one else to wreck him worse than he already is, ready to erupt at any second, quivering like a bowstring.

A key that unlocks his filthy mind, just the sound of Steve saying that warrants a gasping, “Yes. Break 'em, you gotta break 'em.”

"That's my decision, Stark."

"Sir,  _please!_ Make them as big as you can..."

Steve takes another few strips of rope to properly anchor him to the chair, rigging up a harness for his chest and lower torso. The converging red strands web over his stomach and his ribs, placed just tight enough to act like a corset and keep him pulling away. The rigging does nothing to alleviate Tony’s arousal thanks to the icy chill of the oil penetrating his nipples and making them hard as granite, something so much better than the puffiness he dreams about.

Another band of diamond-patterned hemp twists around his shoulders and anchors him hard to the chair, leaving him a submissive picture of glory in the mirror. Steve cares for small touches, and where he found a bright blue ribbon to tie to the base of Tony’s cock he’ll never know or think to ask, especially since the chain linked to it ends up attached to a little steely clamp too small now to fit onto his nipple.

He is too busy staring at it to reckon on the modified forceps clamping his lolling tongue. Muffled sounds of approbation escape his throat as Steve draws the muscle forward, pulling away the soggy hand towel. “Now, you’re going to have to be good and still. We don’t want you spoiling the examination.”  
  
Instantly he goes still and his eyes, glazed and hot, lift to Steve’s face. He accepts the spider gag with as much grace as a drowning man can, the metal fitting at the sides of his lips and secured fully around the back of his head. Steve clicks open the polished metal as easily as any dentist, forcing his mouth properly wide.

He thinks this is the end of his submissive humiliation, but he’s wrong. Steve proves this by holding the forceps again and measuring the furthest Tony’s tongue comfortably reaches. He stares, watery eyed and moaning, as Steve brings up the clamp and opens the jaws wide. It’s toothless, thank the gods, so the closure over the muscle doesn’t hurt so much as pinch. Pressure immediately builds as the attached chain drags his tongue out and his cock back and he instantly understands the beauty of his predicament.

If he’s ever wanted to try autofellatio, now would be the time, but he can’t, and every bob of his head tugs on his swollen dick pointed straight at his face.

Steve massages his shoulders with his huge, warm hands, and then murmurs, “If that clamp comes off, I’m caning your nipples.”

Tony wiggles his tongue. He feels the metal embedded on either side, pressed hard, not enough to numb the tip but close. Always full of a contrary nature, even now, he takes two sharp spanks on his nipple and jolts, only remembering to consciously still his head after he’s pulled his dick sharply up.

The gag makes it impossible to talk and he gurgles around the metal. Drool runs down his chin.

Steve circles around and holds up his smartphone, taking photographs as he moves slowly. Tony raises his head and his eyes widen, but his tongue glistens and his cock throbs even harder, somehow. _Snap!_

Another shot. Another of his big nipple, nice and up close, and a recording of how the flesh stands resistant to being pinched. He will treasure these moments when not blushing red and trying to look away.

The camera is set to the side, basically stuck to a suction cradle on the mirror. Unnecessary since Steve utters that proverbial command aloud. “Friday, get close up shots.”

Ceiling tiles give way and two arms spin down, armed by slender sensory arrays. They move out of the way, but the wide angle should leave nothing hidden. The blond strides out of the way to take up space beside Tony’s chair and reaches for his nipple again, rubbing it gently and coming up with a mini-forcep in soft mint green.

“I need you to hold very still, Stark. That’s an order.”

He waits until Tony nods, eyes widening, his discomfort growing by the second. The filming camera -- and his own AI -- captures the white rims of his eyes as a needle comes into view, prodding lightly at his nipple. In his defense, the width is terribly slim, but he huffs shallow, panting breaths and Steve waits until he masters himself.

“I’m going to pump Banner’s formula into your nipples to stretch them. Once I do that, the effects will go for about seven days.”

He hangs on the blond’s every word, staring down at his teat being sized up by the crenellated pads of the forcep. Little pyramidal studs row on row are meant to hold nice and tight to the skin in surgery and no doubt right now.

“Beg for it, Tony.”  
  
His tongue is clamped, and his mouth pried open by steel. Bliss floods over him as he tilts his head back, feeling the pressure of the forcep tightening down, squeezed on the nipple root until the tip flattens and the sensation makes his balls bounce.

Steve notices that, too. Something to worry about shortly.

“You want your huge nipples, baby?”

“Uh-huh.”

“Beg.”

He swallows noisily. “Leees.” His cock stares at him, an angry shade almost purple, wine-dark and lush. “Lees See.” None of the consonants come out right, slurred and distorted by the gag, and he keeps trying anyways, asking for it, to have the serum and be made better, for his nips to be the way they should be -- long, hard, sticking out from his shirt to get sucked and pinched and spanked. He promises to cum. He promises to let Steve jack his nipples until he sprays his seed on his stomach.

How much Steve hears and understands doesn't matter, not really.

Steve’s eyes sparkle though his expression is stern, and he pulls the nipple cuff aside to push the needle right in to the spot Banner had to instruct him on. It hurts, the cool oil reacting to the presence of the metal, and Tony groans long and low as Steve depresses twenty CCs straight in.

Forceps are applied immediately to the tip of his nipple, dragging it down low, as though Steve expects to serum to spurt out. The tightness backs up the spreading liquid into his puffy areola and gives a nice, long track to be injected again.

The serum isn’t saline and it spreads out, immediately bloating the puffy areola. Tony watches it spread in something like horror and mingled wonder, though genetics and biology aren’t really his fields. He can imagine what happens even when the tingling begins. The next moments are spent extracting another hit off the bottle and shoving that into the base of his nipple, squeezing out double the volume.

Forceps are applied to the other side nice and deep, clamping his reddened nub for some toying. Steve runs his nails over it and twists, using the blood starved tip as his personal toy. A long stub sticks out, and he suckles while Tony groans at the tonguing.

He is glad for the gag or else he might be biting his own tongue watching the strain against the binding cuffs, but they come free one at a time, once Steve has injected a whole bottle into his nip meat. His nipple is sticking out and so _thick_ before his very eyes and if this is all the serum does, like sterile saline, he will be in heaven.

He can't wait to see the film, later. He'll be mounted on Steve's cock and made to watch while Steve gives him pointers on his training. Maybe they can use saline then to give him obscene nubs for Steve to pull and tug as he talks.

Tony has no words.

But the serum does so much more than that, seeping inside, finding those hidden crevices and bulging out the base, giving him the fattest ripe areola he’s even seen on a man. His nipples stand hard and long, getting wider and stretching, really _stretching_. Him. Those are _his_.

Steve greets the other nipple the same and he whines even as the needle pinches deep, the rush of liquid in odd places driving him to distraction. The forceps pinch down and squeeze, keeping all the liquid in place so he gets good and big like Bruce intended.

“You’re probably feeling the aphrodisiac taking hold. He said that might be intense.” Steve flicks the fat point before he anoints it again with an even larger dose.

His bloodstream carries the unknown chemical compounds that leave him lightheaded and dancing between the icy cold dark face of the moon and the burning side. No wonder the extra ropes are needed considering he starts to jerk and spasm as the intense sensitivity ratchets up -- the serum uses his own body against him and he wants a caress on his nipples, finding none.

They are more than red, burning cherry embers, and so utterly suckable and worthy. Steve refrains with the willpower of a man ready to face down the entire Red Army on his own, coming over with sleeved cylinders in acrylic.

Tony may be lost to hell but he knows an industrial milker when he sees one. They have chrome bases and clear tubes, and the tubes wander off to a thicker discharge tube beyond where he can see. There to suck his milk away. There to make him into its willing lover, into Steve's cum slut.

He's getting trained. Really and honestly trained. He aches with hollow need and desire, shaking. He wants this training to never end.  _Pull that off when I stuff the cylinders permanently. Just stuff my hole too. Oh Stevie, fuck me.._

The two arms he suspected to be filming him prove to serve a different purpose entirely, narrowing in on the tubes and swinging into place. His pulse jumps through the stratosphere when red dots appear on his growing nipples, so big, fat berry nubs getting even longer inside the space of a few seconds.

 _What does Banner’s serum do?_ The question is lost in his mind as he cannot ask and Steve refuses to answer, allowing the twin pivoting robots to line up with laser precision. They fit the wide milking cylinders over his nipples, covering the puffy cones in a flat seal.

“You’re going to take thirty minutes of preparatory milking,” Steve announces.

"Unh!"

"Don't be greedy. If you leak, the machine won't stop training your nipples until you pass out and I've drained your balls."

Tony chokes on his appreciation.

"I know you want to be my cum sheath. We'll get there." Steve smiles. "Once we've trained you to come from your nips. You gotta blow when I touch them."

The piece de resistance is a wide tube slid over his cock, silicone laced and stopping at the tip. This way nothing impedes his tongue chain down to the other end up the clamp. Steve fits the tube himself, another thin plastic lead running out of sight. “In case you cum during your milking, we don’t want a mess.”

Tony shudders, since the first whispers of vacuum pressure suck the air out and stretch his nipples into the snug cradles waiting for them. A metal bar is fitted between them by the hydraulic arms, creating a platform for the two acrylic tubes. They line up with pinpoint accuracy into their round cradles. He can't shake them free, and he doesn't want to. He wants them to ravish him.

No such pressure beyond an initial pulse to seal the cylinder around the bell tip of his cock gives relief there. Steve apparently means what he says, which is absolutely always, and he can expect no further suction to play on his cock.

His nipples, however, are enveloped by warm, almost gel-like silk walls that ripple down him. He gapes at the sensation, a little like burying himself in a girl’s hot pussy, except not nearly so realistic for sensation.

The ready suction assures him he knows this is mechanical. The double-walled chamber balances well against the pressure as each pistoning slurp pulls out his fat nubs, stretching them, not sacrificing much of their thickness in the meantime. He can hardly believes what he sees, but the process is a bit like watching a large cock harden up from flaccid softness.

The humming begins as soon as he’s got two and a half inches jammed into the tubes, and another half inch being advanced by hard sucks every couple of seconds. Vibrations shiver through the outer tube and down into the clamped pinch of his areolas, the flat skin drawn up inside. Greedy, the machine demands more and takes it from him, forcing him deeper in until he thinks he'll fill the long cylinders totally.

He prays he does.

Tony drools and bows his head, sacrificing his neck muscles for the slack on his cock. Of course, that will not do for Steve, who makes it his mission to settle behind the chair and push Tony’s head aside.

The other seat is almost forgettable, but the hot mouth branding his throat is not. He runs his tongue up the sensitive line of Tony’s neck to the earlobe, ravaging that soft curve of flesh while the milking begins in earnest.

The inner sleeves jerk back, pulling on Tony’s nipples. They demand he stretch to fit and the relentless pull begs for his huge nubs to give up sprays of milk. He starts to shudder, still given a little room to rock his hips, but he cannot get anywhere without dragging on his protruding tongue.

Steve sucks his throat and shoulder, biting down when the mikers adjust and start punch-fucking his nipples hard and deep. He wants to scream but the sound is lock in his throat, and Tony drools copiously as he watches his raspberry nubs take their due by the pitiless mechanisms. Banner’s serum puffs and stretches them, he can see that now, and he can barely understand why his tits burn and tingle so much.

The two minute mark passes when the first spurts of his white semen plaster the inside of the tube sealed tight to his cock.

By five, he is begging in broken tongues to be fucked. His big nipples are relentlessly ravaged the same way the Chitauri spanked and stung them, turning them the prettiest shade of red. His are a much different hue, and the measured grades on his milking tubes shows his progress, if his broken mind could fathom more than his need to please Steve.

By ten, he's shuddering as the milkers hit on high and abuse his tits, stretching them out incredibly long and stinging them with short shocks to force them to stiffen out. They are so thick, so firm, they can fill the gel inserts that coat them. Electricity dances into their roots and the serum continues its magic.

Tony is so proud, even as he begs and chants for more. What he wants, he gets.

* * *

 

Captain Rogers leaves his welted neck alone for a time, the better to fist his cock in his hand and apply a pair of ball separators around Tony’s sack. They lift and separate his testes, parting them wide to the sides.

As much as a vibrator would fit perfectly there, the churn of his cum belongs only to his nipples being stimulated and, with the press of a button, shocked by the tubes that hold and jiggle his tits around to disperse the serum evenly.

Steve returns with another vial to distribute, and he does around the hard tubes slurping up his boyfriend’s nipples. Tony doesn’t even look up when it happens, his head hanging forward, eyes fixed on what his tiny, sensitive nodules are transforming into. Another twenty CCs a side should do the trick, though Bruce kindly allotted a hundred for each. No telling the levels of Tony’s depraved needs.

The sensitivity is skyrocketing with every second, and he has another ten minutes to wait while the handsome blond pulls a condom on and starts to masturbate aggressively. He watches the outlay on the wall by the various sensors measuring Tony careening from one orgasm to another.

Normally this might be a risk but not with the stimulants and the suppressants worked into his protein shakes for the past two weeks. The incident in the shower only proved how well the concoction works and every climax only serves to make Tony Stark more eager and horny, his cock drooling gently as it splatters a load fresh upon the last.

Twenty-nine minutes exactly marks the point when the first speckles of milk erupt out of Tony’s throbbing nipples, the steady lubricated slurping producing the results they both want so bad.

He leaks a little gush and then the fine ducts at the tips of his nipples pour out more, spitting a wet mist into the greedy tubes. The machine doesn’t change or alter its progress any but Steve leaps off the table and rushes over to watch.

Fine cream coats the interior by the time he reaches Tony, little puddles gathering around his conical bases where beads collect down.

“You’re being milked,” he whispers into his boyfriend’s ear, stirring him from the fugue. “Look at those big leaking nipples.”

What can Tony do but gasp in huffs?  _Milked. Yes, yes, milk his nips, make the milk spray out like cum._

"You did it. I knew you wanted it. Give it up, Tony, give me your milk."

The blond palms one of the stiff cylinders so Tony can watch the dark nipple jutting out long and pushed back in, mechanically forced to gush out its load. The other half of Bruce’s formula finally becomes clear as the spray increases, simulating a pregnant woman’s let down, and then he starts to churn out milk in earnest. It makes him scream in his gag, eager and shaking with pent-up force. The force only increases as if the machine knows it has to make him leak, ravaging him to get him to spill.

Steve kisses his neck again, and heads off to get the table. With that he can get enough of a platform for what he needs.

The wet sprays filling the tubes increase in volume as the forceful slurping of the milking machine demands its due. Tony gulps for air through his gag, almost catatonic by the time Steve mounts the table on his knees. He is gentle to cup the back of the brunet’s head and line up his cock to the gaping wet void of his mouth.

Tony chokes on the enormous shaft rammed into the back of his throat. Steve is far too much for his mouth, the veined length choking his windpipe and holding down his taut tongue while the clamp pinches in tight.

His cock is strained too by the chain, pointed at his face, the fine tube whipping around as his body shakes. Steve’s hands planted around his skull give him no escape from being face fucked -- _throat fucked, mouth raped, skewer me baby, oh fuck yes_ \-- on the super soldier’s dick.

It’s so much that he can never force himself to deep throat very well, and Steve does that for him, ramming the tip into his stretched throat and lower.

The milk oozes out of him in gushing sprays that fill the tubes and slide down. His nipples ache, so hard and thick, but they perform as requested. He can’t breathe for the cock-meat filling the spider gag, forcing him to drool copiously along with the precum glistening on his lips.

The video gets it all, right down to the bulge in his neck marking where Steve face fucks him properly. Just like with the Chitauri void, he is wet and willing.

Steve never tires. He doesn’t flag with that heroic stamina and even when he does, the serum in his veins ensures his refractory time is obscene. He may not last fast the first time, but he pulls off the condom when he is ready to blow and luxuriates in Tony’s outstretched tongue, the feel of it writhing along his underside veins.

Tony is lost to the world, used and mindlessly writhing, giving up everything he has. His orgasms roll through him as he bucks against the bindings on his balls and cock, the ribbon flapping around beautifully for the camera.

Cameras. He has no idea how many people film him or who will see, except Steve. Steve pounds his mouth wetly through his weakened gag reflex, giving him those breathless, exhilarating orgasms at the threshold of passing out.

All the better, for the fifteen minutes longer he takes his training until his nipples can draw out no more milk no matter how hard the machine tries.

When Steve toys with one of the tight seals dragging in low, strong pulses, Tony makes incoherent sounds of protest and shakes his head around the unfailingly hard cock reaming his throat, his glassy belladonna eyes turned up to the soldier in wordless plea.

“Oh, baby. I’d never take them away if you still wanted them.”

Tony quiets somewhat, slack and welcoming around the mushroom tip leaking cum down the back of his throat into his belly, a warm glow filling his limbs. He lets the machine slurp and pull his nipples out far, so far, jamming the cylinders with his stiff raspberry flesh. Not as good as Steve sucking him, but that's going to come soon, he's sure. 

“Looks like the serum worked.”

Steve taps the cylinder firmly.

He gags around the huge cock robbing him of speech and breath, the first tightening in what feels like an hour. A few light spanks has him slurping desperately and Steve's balls tighten, sending another gush spilling into Tony's mouth and leaking out past his spread lips.

The hum of a sigh follows his announcement and Steve brushes his hand over the dark hair matted by perspiration to the genius’ brow.

 

* * *

 

Eventually the table is moved back and the cock he gagged on removed, an ample amount of Steve’s cum serving to offset the dehydration of losing much water through saliva coating Tony’s chest.

The super soldier manages not to stumble seeing his lust-stricken boyfriend totally wrecked and ready for the finishing touches.

He takes the barbells and the piercing set over to two more mechanical arms. In this, he trusts the technology far more than himself.

“Friday, commence with procedure twenty, codeword ‘cherries jubilee.’”

“Good afternoon, Captain Rogers. Voice authorization permitted.” Friday always sounds so pleased when called on, and maybe in her way, she is.

“Thank you.” He never loses his manners, even as _Epsilon_ becomes a flurry of activity. “Can you manage another two injections as part of the process?”

“Doctor Banner’s notes indicates four would be the maximum safe volume at this time. Yes, I can.”

Steve cocks his head, holding out the barbells for the oversized metal pincers to pull away with incredible delicacy as they pirouette and gather the necessities.

“Is that your hint I should give him four?”  
  
“I wouldn’t ever presume, Captain Rogers.”

“Gotta love you, Friday. Does _Tony_ have a preference?”

“Six.”

“Figures. The man wouldn’t know restraint if it bit him on the nose.” He sighs and rubs his face with the palm of his hand. “Four. Reserve two for later. Monitor him and if there's any shrinkage, give him more. He wants the most he can get.”

“Yes, Captain Rogers. You enjoy yourself.”

Being told off by a machine, _that’s_ new. He turns his head to watch Friday execute on his request and Tony’s protocol and half a dozen other hidden hands in the pie. Right now being buried in his boyfriend’s ass would be desirable, but nothing can be allowed to interfere.

 

* * *

 

When the sucking cylinders yank away, disengaged by careful pressure, Tony instantly whines around his gag and snaps his head back. The clamp finally surrenders his tongue and he feels the tension of the chain land heavily around his beribboned cock. Even that much sends him into spasming raptures, his torment from an unexpected quarter redoubled by the smooth links wrapping lazily across his bound balls.

Steve has replaced the ball stretchers three times by order to the AI and this time the silicone feels stretched to the breaking point. He has no concept of what the serum has done to his nipples, but the tubes are gone and his nipples can’t leak precious milk without them.

Tony lies prostrate and limp in the seat, held up by the ropes. He has no energy at all to protest when the cold swab of liquid runs over his milked tits, washing away the lubricants poured over him to keep his distended nubs pliable and stiff.

They’re almost purple given the blood swollen into them and the concoction of the serum made by Bruce Banner’s clever hands. Tweezer clamps slide into place immediately, tightened up to the point his nearly numb senses tingle. Red dots glow, turning green with a rotation of the levered arms.

He has no time to consider what those mean, since the needles line up to the dots and simultaneously press in on his hardened, fat nubs until the pointed ends sink in. Pain flowers and he jerks in place but Steve -- _oh fuck hurts_ , _sparkling hot, hard tug fuck fuck_ \-- gently massages his shoulders and caresses his jaw.

Friday guides thick gauge barbells into place, sliding the titanium shafts into place with the most enormously odd sensation. Selected for the terminal ends, the machinery screws on snug rubies and sapphires set in round balls, pinching his conical areolas with their new jewelry.

At the same time, the needles sink into him to plunge more of the serum into his tits, forcing his nipple to stick out even more than he ever thought they could. The cooling gel sprays in a fine mist and any minute amounts of blood are washed away by the hypoallergenic, sterile liquid puffed over him.

Tony hangs there like a stunned broken doll, and Steve adds the final touch himself: the nipple stretchers, round cones guided around the distended nubs.

The view deprived is for a purpose. Tony Stark can wait to see the effects once he has woken up, bucking for an orgasm deprived to him.

Steve smiles as only the huge tips stick out, giving the nipples a time to grow used to the piercings and their new heights. He desperately hopes that Banner was right and Tony’s genetics will make the serum permanent, but neither of them will be sure. It will have to be unveiled soon enough, when his boyfriend returns to some kind of conscious state instead of dripping milk and cum from his drained balls.

Perhaps he’ll unveil the effects to a select few of their friends with Tony mounted over the table, begging for more in his ass and his nips to be milked again.

“Hey, Friday,” he says as he reverently unties Tony’s ropes. “Will you send a message to Sam and Clint, top secret?”

“Yes, Captain Rogers. Contents?”

“Test subject 353.”

“Sent,” she confirms.

The checklist is already growing in Steve’s mind as he carries his near-catatonic lover out of the room. They’ll need rest, first, he thinks as he heads to the clinical bay.

His slut’s ready for his close-up.

**Notes for the Chapter:**

> Test Subject 353, which is part three of Skeleton Key, puts Tony on the table -- or in the chair -- while being medically examined and recorded during the process. Want me to cover a topic? Leave a comment


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